ZFX + Developia

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#include <intrin.h> // '__cpuid' intrinsic

typedef int CSignedInteger4Bytes;
typedef unsigned int CUnsignedInteger4Bytes;
typedef char CASCIICharacter;
#include <string>
typedef ::std::string CASCIIString;

//--------------------------------------------------------------------------------------------------------------------------
// Returns the current CPU's brand string (e.g. "Intel(R) Core(TM) i7 CPU         860  @ 2.80GHz").
// If the CPU doesn't support this feature (< Pentium IV), "unknown" is returned.
//--------------------------------------------------------------------------------------------------------------------------
CASCIIString CPUBrand() {
	// This function uses the 'CPUID' instruction via intrinsic to retrieve the CPU's built-in brand string.
	// For the '__cpuid' intrinsic and an explanation of its parameters, see http://msdn.microsoft.com/library/hskdteyh.

	// First, it is determined whether the CPU supports extended CPUID functions by checking if 0x80000000 returns a higher
	//	value in EAX. If it does, the values 0x80000002 through 0x80000004 can be used to retrieve the brand string[1].
	CSignedInteger4Bytes eaxEbxEcxEdx[4];
	__cpuid(eaxEbxEcxEdx, 0x80000000);
	// consider: '__cpuid' expects signed 4-byte values, but 0x80000000 is unsigned
	if(0x80000000u < CUnsignedInteger4Bytes(eaxEbxEcxEdx[0])) {

		// The brand string itself is an ASCII string with a maximum length of 47 characters; with 4 characters stored in
		//	EAX, EBX, ECX and EDX each, for three CPUID calls[2].
		union {
			CASCIICharacter			characters[48];
			CSignedInteger4Bytes	registers[4 * 3];
		} processorBrandString;

		__cpuid(processorBrandString.registers    , 0x80000002);
		__cpuid(processorBrandString.registers + 4, 0x80000003);
		__cpuid(processorBrandString.registers + 8, 0x80000004);

		return CASCIIString(processorBrandString.characters);
	} else
		return CASCIIString("unknown");

	// [1] "Intel® Processor Identification and the CPUID Instruction", May 2002, Order Number: 241618-021, pg. 21:
	//		"To determine if the brand string is supported on a processor, software must follow the step below:
	//			1. Execute the CPUID instruction with EAX=80000000h
	//			2. If ((returned value in EAX) > 80000000h) then the processor supports the extended CPUID functions and EAX
	//				contains the largest extended function supported.
	//			3. The processor brand string feature is supported if EAX > 80000000"
	// [2] "Intel® Processor Identification and the CPUID Instruction", May 2002, Order Number: 241618-021, pg. 21:
	//		"The brand/frequency string is defined to be 48 characters long, 47 bytes will contain characters and the 48th
	//		byte is defined to be NULL (0). A processor may return less than the 47 ASCII characters as long as the string
	//		is null terminated and the processor returns valid data when CPUID is executed with EAX = 80000002h, 80000003h
	//		and 80000004h."
}

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